This invention relates, generally, to liquid natural gas (LNG) delivery systems and, more specifically, to a no loss fueling station for LNG particularly suited for use with natural gas powered motor vehicles.
In recent years great efforts have been made to find a cheap and reliable domestic energy alternative to oil. One such alternative fuel is natural gas which is domestically available, plentiful and relatively inexpensive and environmentally safe as compared to oil. Because one of the largest uses for oil is as a fuel for motor vehicles, great strides have been made to develop engines which run on alternative fuels such as natural gas.
One such engine runs on a 60/40 diesel fuel to LNG mixture which requires that LNG be delivered to the engine at approximately 300 psi, a pressure approximately 6 times the normal storage pressure for LNG. Other natural gas powered engines require that the LNG be delivered at pressures ranging from less than 50 psi to more than 500 psi. Therefore, a LNG fueling station that can deliver LNG to vehicles having wide variations in delivery requirements is desired.
Moreover, LNG is an extremely volatile substance that is greatly affected by changes in pressure and temperature. As a result, the fueling station must be able to accommodate fluctuations in pressure and temperature and transitions between the liquid and gas states. Further, the fueling station must be able to deliver LNG to vehicle fuel systems which are under various pressure and temperature conditions. Optimally, the fueling station should be able to meet these conditions without wastefully venting LNG to the atmosphere, i.e. the fueling station should result in no loss of LNG or natural gas.
Thus a no loss LNG fueling station that can efficiently deliver LNG through a range of temperatures and pressures is desired.